1. Field of the Invention
This invention relates generally to an adjustable depth sheet feeding tray wherein a predetermined number of sheet articles may be fed, one at a time, to a catch tray assembly adapted to be attached to the frame of a sheet feeding machine in which a predetermined number of sheets can be accumulated and readily removed as a unit and where the removal of the sheet articles activates the sheet feeding machine for another cycle of sheet feeding to begin.
2. Description of the Related Art
In the applicants U.S. Pat. No. 6,050,563 and entitled xe2x80x9cSheet Feederxe2x80x9d issued Apr. 18, 2000, there is described an improved friction sheet feeder for feeding sheet-like articles, such as paper sheets, paper cards, plastic sheets or other flat products from a stack of such sheets contained in a hopper, one a time. The contents of that patent are hereby incorporated by reference. The machine therein described is readily suited to dealing out individual sheet articles to a collating conveyor where other sheet articles distributed from a different sheet feeder are combined to form a booklet or the like.
In certain applications, it is desirable to be able to rapidly accumulate a predetermined count of identical sheet articles for later boxing or packaging. Consider the case of greeting cards. A greeting card publisher may often wish to box or wrap 20 greeting cards and 20 envelopes as a unit. Sheet feeding equipment of the type described in applicant""s above-referenced patent can readily be programmed to deal out 20 cards while a second such machine deals out 20 envelopes. When this is to be done on a repetitive basis and with a human operator taking the groups of 20 cards and 20 envelopes and placing them together for further processing, e.g., wrapping or boxing, it would be advantageous to have the removal of a set from a receptacle initiate another cycle of the sheet feeding machine so that as a first set is being inserted by an operator into a box, the sheet feeder can already be dealing out another set of sheet articles.
In applicant""s U.S. Pat. No. 6,206,363 entitled xe2x80x9cCatch Tray Attachment For Sheet Feeding Machinexe2x80x9d issued Mar. 27, 2001 an accessory attachment for a sheet feeding machine electronically tied to the sheet feeder""s motor controller, and having a signal sent to the sheet feeder to activate it for a predetermined number of sheet delivery cycles upon the removal of sheet articles from a catch tray was taught. The contents of that patent are hereby incorporated by reference.
The present invention improves on the U.S. Pat. No. 6,206,363 patent by providing a depth adjustment for the catch tray and having a substantially open bottom to the tray with a support plate for preventing the sheets in the catch tray from sagging in the middle of the sheets length. However, for narrow sheets or stiff products the support plate is not necessary and can be easily removed.
The present invention comprises a catch tray attachment for a sheet feeding machine of the type comprising a frame, an endless feed belt and a feed belt drive motor structure supported by the frame for driving an upper flight of the endless belt in a forward direction. Positioned above the upper flight of the endless belt is a hopper that supports a stack of sheet articles such that the lowermost sheet article in the stack contacts the upper flight of the endless belt. A stripper wheel cooperates with the upper flight to block all but the lowermost sheet article from passing between the stripper wheel and upper flight along a discharge path. The sheet feeding machine with which the catch tray is used further includes a microcomputer-based control circuit for controlling the drive motor structure.
The catch tray itself comprises a tray member having a generally planar base with first and second sides projecting perpendicularly to the base where each of said sides includes a longitudinal extension adapted for connection by bolts or the like to the frame of the sheet feeding machine so as to locate the tray member downstream of the discharge point of the sheet feeding machine. A stop assembly is suspended between the first and second sides and includes a stop member that is disposed in the discharge path of the sheet articles exiting the sheet feeding machine to cause sheet articles to drop onto the base ahead of the stop members. A sensor, such as a photo eye, is mounted on the base for detecting the removal of sheet articles from a resting position on the base and sending a control signal to the control circuit of the sheet feeding machine for restarting the motor a predetermined time after sheet articles fed from the sheet feeder are removed from the catch tray.
It is an object of the invention to provide a sheet tray for a sheet feeder which is easily adjustable for the length width and depth of the sheets fed into the sheet tray.
It is an object of the invention to provide side walls in the sheet tray which are adjustable in two dimensions.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing.